<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>05_元素显示模式</title>
    <style>
      div{
        width: 100px;
        height: 100px;
        border: 1px red solid;
        /*块级元素可以设置宽高，元素竖着排
        div高度默认是0，宽度默认是父类宽度100%*/
        display: block;
      }
      .d2:hover{
      background-color: pink;
          display: none;
      }

    </style>
</head>
<body>
<div class="d1">111</div>
<div class="d2">222</div>
<div class="d3">333</div>
<p class="p2">jkl</p>
</body>
</html>